Devices which use batteries as a source of power are well known. Such devices include, but are not limited to, portable radios, portable communications devices, and medical devices such as hearing aids.
Most devices that use batteries as a power source provide an access panel or the like which allows the user to install or replace the batteries. Such access by the user increases the possibility for human errors. One type of human error that is frequently encountered is a battery polarity error. A battery polarity error occurs when the user inserts the battery in the device with a reversed polarity. As a result of the error, the positive terminal of the battery is connected to the negative power terminal of the device and the negative terminal of the battery is connected to the positive terminal of the device. With the battery connected to the device with a reversed polarity, the device will generally not work or, in some instances, may be damaged. Even in the absence of permanent damage, a polarity error can be a source of frustration to the user, particularly when the battery is a disc-type battery, such as the type used in a hearing aid, since it is often difficult for the ordinary user to discern between the positive and negative terminals on such batteries. As such, it may be difficult for the user to perform the initial installation correctly and to subsequently diagnose the polarity insertion error. Additionally, mechanical damage to a hearing aid may be caused by reverse insertion of the battery resulting in the return of the hearing aid to the manufacturer for repair.